The present invention relates to improvements in a method and machine for the production of so-called hinged-lid or flip-top packs for groups or blocks of plain or filter-tipped cigarettes, cigars, cigarillos or analogous rod-shaped articles. More particularly, the invention relates to improvements in a method and machine for the making of hinged-lid or flip-top packs of the type wherein an outer envelope consisting of relatively stiff material and embodying a pivotable lid surrounds at least one inner envelope which consists of relatively soft and readily foldable material, and wherein the pack further includes an insert of the type known as collar and serving to yieldably retain the pivotable lid in closed position as well as to guide the lid during movement between open and closed positions. The insert is normally secured to the internal surface of the outer envelope and is provided with at least two edge portions which guide and/or retain the pivotable lid.
A presently known machine for the making of hinged-lid packs for groups or blocks of cigarettes or analogous rod-shaped articles includes devices for surrounding a group of rod-shaped articles with a preferably two-piece inner envelope consisting exclusively of metallic foil or of soft paper which is lined with metallic foil. One section of the inner envelope is removed by the purchaser upon opening of the pack (i.e., upon completed pivoting of the hinged lid to its open position) to thus afford access to the adjacent ends of articles. In the next step, the collar is placed around the inner envelope so that it partially surrounds three sides of the inner envelope. This collar normally consists of relatively stiff paper or cardboard and its central panel is placed over the overlapping portions of the two sections which form the inner envelope. The blank which is to form the relatively stiff outer envelope is first converted into a substantially U-shaped body during transport on a chain conveyor and the group of articles (with the inner envelope and collar therearound) is thereupon placed into the U-shaped body. The chain conveyor continues to transport the U-shaped body past a series of folding members serving to convert the body into a tube which is closed at one end and is provided with a hinged lid at the other end.
A drawback of the just described packing machines is that their output is very low, normally only half the output of a modern high-speed machine for the production of plain or filter tipped cigarettes. Therefore, such packing machines cannot be directly coupled to machines for the mass-production of tobacco-containing rod-shaped articles because each producing machine turns out a number of articles which suffices for the processing in several packing machines.
It is further known to produce hinged-lid packs on a rotary turret. Each group of rod-shaped articles is first completely surrounded by an inner envelope of relatively soft material. The blanks which are to be converted into outer envelopes of the packs are treated on two successive conveyors the first of which cooperates with means for folding selected lateral flaps of the blanks and the second of which cooperates with means for folding certain additional flaps so that each blank resembles a U-shaped body which receives the inner envelope with a group of rod-shaped articles therein. The final steps of conversion of blanks into outer envelopes are carried out while the blanks move with a further turret. Thus, the final folding steps are performed while the blank for the outer envelope already contains a group of rod-shaped articles so that the articles of such group are likely to be deformed even if the blanks for the outer envelopes are provided with weakened (grooved or perforated) portions to facilitate folding during conversion into outer envelopes.
It is also known to produce so-called soft cigarette packs by draping blanks of relatively soft and pliable material around hollow mandrels which receive groups of rod-shaped articles. However, such procedure was never employed for the making of hinged-lid packs wherein at least one component consists of relatively stiff sheet-like material, such as a cardboard with a weight in excess of 150 grams per square meter. As a rule, a soft pack comprises an inner envelope of thin metallic foil and an outer envelope of soft paper.
A drawback of all presently known machines for the making of hinged-lid packs is that they produce an excessive number of rejects. Thus, if a conventional machine fails to deliver a single component of a hinged-lid pack or a single group or block of rod-shaped articles, the corresponding pack must be discarded which entails substantial losses in tobacco and/or in material of the packs. Moreover, the operation of the machine must be interrupted at frequent intervals, either due to malfunctions which are caused by defective packs or in order to remove one or more defective packs or portions of packs. As a rule, the defective packs or portions thereof must be removed by hand.